How to grow a Venus Flytrap

Venus
Flytrap Care Sheet

Dionaea
muscipula

Probably the best-known plant
carnivore, Venus Fly Traps are not difficult to grow when provided with the
proper care. These plants are not only fun to grow but educational as well,
providing an ideal introduction to the strange world of nature for children of
all ages. One of the biggest misconceptions about these plants is that they
hail from some steamy, tropical locale, bathed in moisture and humidity. In
reality, these plants are probably more similar to garden perennials than
tropical species.

In nature these plants are found
growing in the open, sunny and damp grasslands of southeastern North Carolina
and extreme northeastern South Carolina at the edges of swamps and ponds in a
peaty and sandy soil. Although the conditions are warm and humid, the plants do
not like stagnant air and enjoy several hours of direct sun each day. During
winter, the plants go dormant in response to the shorter days and colder
temperatures.

In order to successfully cultivate
the plants it is a good idea to first get a better understanding of their
natural history and try to replicate their needs

How the Plant Grows:

The growth cycle of a Venus Fly Trap
follows the four seasons with different types of growth in each. In spring, as
the plants emerge from dormancy, the plant will produce a rosette of short
leaves that hug the surface of the ground with a trap at each tip. The plant is
usually not too large at this point, perhaps 2”-4” across. It is also at this
time that a tall spike bearing several white flowers will appear.

As summer sets in a different type
of leaf is produced. Now, instead of hugging the ground, taller, more upright
leaves begin to grow holding the traps several inches above the soil. The traps
also change in appearance, being larger overall and having a semi-circular
'notch' in the back. New leaves with traps are constantly being produced to
replace the older, dying ones.

Once the days begin to shorten and
the temperature starts to drop in fall, a smaller, flat rosette is once again
produced, very similar to that of the spring growth. The plant is now preparing
for dormancy.

In winter, the plants are semi
evergreen and will retain few to several leaves depending on how cold it gets.
The leaves are quite tolerant of frosts but extended cold will eventually cause
them to die back. Underground, the plant is still quite alive. A scaly
bulb, similar to a tiny lily, is resting and building up strength to begin
growing even larger the following spring.

How the Trap Works:

Anyone who has watched a Venus Fly
Trap snap shut on its prey has been awed at the quick response and seemingly
conscious reaction. The trap appears to somehow know when something is within
it's reach and can quickly snap the sides of the trap shut on its hinged spine.
In reality, none of this is true, although the actual functioning of the trap
is no less amazing. When you look closely at the inside of the trap wall you
will notice 6 tiny hairs, 3 on each side. Called trigger hairs, it is their
sensitivity that gives the plant the ability to know when something is inside
the trap. In order for the trap to close, two separate triggers hairs must be
touched or one of the hairs must be touched twice. Once this happens the trap
will quickly shut, trapping the prey.

Although the trap appears to be
somehow hinged along the back, this is not actually the case. The closing and
opening of the trap is all a growth process, albeit a quick one. When the first
trigger hair is touched, it sends out an electrical signal to the leaf tissue
where it is stored. When the trigger hairs are touched again a second impulse
is sent out causing the outer layer of cells in the leaf to instantly grow by
25%. The result is that the leaf quickly grows shut. If a suitable meal is
caught, the edges of the trap will press tightly together as digestive juices
flood the interior. After digestion occurs, the inside layer of cells begin to
grow until the trap is open once again. This results in the trap increasing in
size by 25% each time. It is for this reason that it is not healthy for the
plant to be tricked into closing without being fed too often as a great deal of
energy in put into the whole process. If the plant is not getting nourishment
it will eventually weaken the plant.

Fly Traps
can be grown in bog gardens, bog terrariums or even on a sunny windowsill as
long as the proper conditions are provided. For windowsill culture, the plants
should be left in their pots and set into a tray or container that will hold at
least an inch of water. Distilled or rain water should be poured into the tray
to a depth of approximately 1" and the pots set down into it. The pots
should never be allowed to dry out. The plants should be placed in a window
that will receive a couple hours of sun daily. Morning sun is best as afternoon
sun can scorch the plants as it comes through the glass. Feeding the plants is,
after all, one of the greatest joys of owning carnivorous plants but needs to
be done in moderation. Only small, soft-bodied insects should be fed to the
plants. Overfeeding can kill a leaf and if done in excess can actually kill the
plant. Never feed such things as hamburger, raw meat or large insects as they
are not digestible and will quickly rot the trap.

Providing natural sunlight will also
help the plant to know when it is the proper time for dormancy. This will be
stimulated by the shortening day length of fall. As dormancy approaches the
plant will produce shorter leaves until only a small rosette of leaves remains.
It is at this time that the plant will require cooler temperatures to enter
full dormancy. The pots should be allowed to drain, but not become dry, and
then be moved to an area having temperatures of 35 to 45 degrees. Suitable
areas would include an unheated basement or spare room or the plants can even
be overwintered in the crisper drawer of the refrigerator. If storing in the
refrigerator first seal the plant, pot and all, in a plastic Ziploc bag to
prevent desiccation. Light is not important for the plant at this time but they
should be checked periodically through winter to ensure they are not drying out
or starting to rot. Winter dormancy is very important to these plants as if
they are forced to grow throughout the year they will eventually run out of
energy and perish.

As the days begin to lengthen in the
spring, the plants can be brought out of their resting place and gradually
exposed to their original growing spot and normal culture should resume. It is
at this time that the plants will normally flower and an increase in size
should be noticed over the following year. Repotting can also be done at this
time using either peat moss or a mix of peat and sand. Never use garden or
potting soil, as they do not provide the acidic conditions the plants require.

Growing the plants in bog terrariums
is virtually the same however the main difference is that the plants are not
left in their pots and providing appropriate lighting is extremely important.
Standard ten gallon or twenty gallon 'long' aquariums work well as they allow
sufficient room for the plants but are not too tall. The substrate in the tank
can be either straight peat moss or a mix of peat and sand. The mix should be
kept damp to wet at all times so a drainage layer is not necessary. It is
important to use only distilled or rain water as minerals will quickly
accumulate in a closed system such as this. Since the plants do best with at
least some direct sun, providing them with at least 40 watts of fluorescent
lighting at a height no more than 8”-10” above the plants is best. If the
terrariums are too tall it can be difficult to provide the light intensity
required. The day length provided should fluctuate seasonally to tell the
plants when to grow and when to go dormant. The whole terrarium can be moved to
a cold basement or unheated room for the winter. Alternatively, the plants can
be uprooted from the terrarium and placed in Ziploc bags with some damp peat
moss and over-wintered in the refrigerator.

By far the easiest way to grow these plants is outdoors in bog gardens. In
almost every part of the US with the exception of the hot, dry desert
southwest, plants grown in this way are far superior to those grown behind
glass. Bogs can be as simple as an undrained container with a minimum depth of
8” and minimum width of 12”. The container is filled with a peat and sand mix
and the plants are planted directly into it. A top dressing of sphagnum moss
will help prevent the peat from splashing up during rain storms. The bogs are
kept wet at all times and placed where they will receive several hours of
direct sun every day. The plants feed themselves and the growth rates, plant
health and color are phenomenal. Being exposed to the full elements outdoors
enables the plants to know when it is time to bloom, grow and go dormant. In
all but the coldest areas of the country the bog gardens can be left outdoors
year round. In severe winter areas the plants are best over-wintered in cold
basements or by using the refrigerator method described above.